A COMPARATIVE ANALYSIS OF LEARNERS INTERACTION IN THE ONLINE LEARNING MANAGEMENT SYSTEMS: DOES NATIONAL CULTURE MATTER?

Open and distance learning (ODL) connects learners across geographical boundaries. Through the support of the Internet and Learning Management Systems (LMS), learners nowadays are conveniently learning and communicating via the online mode. Nevertheless, will the cultural diversity of learners affect their learning and interaction behavior in the web-based environment? This is viewed as one of the relatively unexplored scope of research areas worthy investigating via a comparative analysis of two countries from Asia but with different contexts of society. This article investigates the learners' online interaction of two open universities, namely Shanghai TV University in China and Wawasan Open University in Malaysia. Based on the findings of this comparative study, the authors are of the opinion that national cultural diversity of learners affects and influences their learning and interaction behavior in the online platform. The effect of cultural diversity of learners is in fact prominent in several aspects in their online learning and interaction behavior as observed in the synchronous chat sessions and asynchronous forum board discussions. In order to better guide the learners as well as to eliminate the negative impact of national cultural diversity on learning outcome, several suggestions and recommendations are proposed

A comparison about the inhibitory effect of curcunmin and Avastin on the rat corneal neovascularization

AIM: To compare the inhibitory effect of curcunmin and Avastin on the rat corneal neovascularization(CNV), and approach the mechanism of the curcunmin's inhibition. METHODS: CNV was established in thirty SD rats by alkaline burning. Rats were divided equally to group A and group B at random. In group A, right eyes were experimental group A1, treated by 40μmol/L curcunmin solution, and left eyes were control group A2, treated by 0.09% sodium chloride. In group B, right eyes were experimental group group B1, treated by 5g/L avastin, and left eyes were control group B2, treated by 0.09% sodium chloride. Cornea and aqueous humor were collected by time spot. The capillary vessels were study, and the expressions of VEGF were detected by Enzyme-Linked immunosorbnent Assay(ELISA). RESULTS: No toxic effects of the drugs were found. The capillary vessels in experimental group were less than those of control group(P<0.01). No statistical different of the capillary vessels between two drugs were found. The expressions of VEGF in experimental group were less than those in control group(P<0.01). The expressions of VEGF in B1 group were less than in group A1. CONCLUSION: The inhibitory effect to CNV of curcunmin and avastin have no statistical different in the experiment, but curcunmin has the less inhibitory effect to the expressions of VEGF than avastin. Curcunmin may have other mechanism in the inhibitory action on CNV

Multiscale Combined Model Based on Run-Length-Judgment Method and Its Application in Oil Price Forecasting

Forecasting of oil price is an important area of energy market research. Based on the idea of decomposition-reconstruction-integration, this paper built a new multiscale combined forecasting model with the methods of empirical mode decomposition (EMD), artificial neural network (ANN), support vector machine (SVM), and time series methods. While building the model, we proposed a new idea to use run length judgment method to reconstruct the component sequences. Then this model was applied to analyze the fluctuation and trend of international oil price. Oil price series was decomposed and reconstructed into high frequency, medium frequency, low frequency, and trend sequences. Different features of fluctuation can be explained by irregular factors, season factors, major events, and long-term trend. Empirical analysis showed that the multiscale combined model obtained the best forecasting result compared with single models including ARIMA, Elman, SVM, and GARCH and combined models including ARIMA-SVM model and EMD-SVM-SVM method

Effects of salidroside on rat CYP enzymes by a cocktail of probe drugs

Objective(s): In this study, we aimed to evaluate the effect of salidroside on the activities of the different drug-metabolizing enzymes CYP1A2, CYP2B6, CYP2C9, CYP2D6 and CYP3A4 in rats, in which a specific probe drug was used for each enzyme. Materials and Methods: After pretreatment with salidroside, five probe drugs were simultaneously administered to rats by gavage. The given dose was 2.0 mg/kg for phenacetin (CYP1A2 activity), 4.0 mg/kg for bupropion (CYP2B6 activity), 2.0 mg/kg for losartan (CYP2C9 activity), 8.0 mg/kg for metoprolol (CYP2D6 activity) and 1.0 mg/kg for midazolam (CYP3A4 activity). Then, an ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to analyze the concentrations of rats’ blood, which were collected at different corresponding times. Results: Our data showed that salidroside exhibited an inductive effect on CYP1A2, CYP2B6, CYP2C9 and CYP3A4 activities by changing the main pharmacokinetic parameters (t1/2, CL/F, Cmax and AUC(0-∞)) of the four probe drugs in rats. However, no significant changes in CYP2D6 activity were observed. Conclusion: In a word, the results displayed that salidroside could induce the activities of CYP1A2, CYP2B6, CYP2C9 and CYP3A4, which may influence the disposition of the drugs that are mainly metabolized by these pathways. Our research can provide the basis for the study of related herb-drug interactions in clinic

Pre-Late Eocene position of the Lüchun-Jinping microblock in western Yangtze Craton: constraints from Eocene-Oligocene lamprophyres in southeastern Tibet

The tectono-magmatic history of the Lüchun-Jinping microblock and its possible affinity with the Yangtze Craton are important elements for the reconstruction of Cenozoic plate tectonics in southeastern Tibet. In order to constrain the affinity and decipher the pre-Cenozoic paleopositon of the Lüchun-Jinping microblock, we focused on the petrogenesis of Eocene-Oligocene lamprophyres in the Lüchun-Jinping microblock. The lamprophyres yield zircon Usingle bondPb ages of 34.7–33.3 Ma and exhibit potassic-ultrapotassic features with elevated K2O/Na2O (1.4–4.0) ratios. They are characterized by high concentrations of compatible elements (e.g., Cr = 187–692 ppm, Ni = 31–218 ppm), large-ion-lithophile elements and light rare-earth elements enrichment, high-field-strength elements depletion, and high radiogenic isotopic values, i.e. (87Sr/86Sr)i = 0.7063–0.7078 and εNd(t) = −3.9 to −2.4. Combined with the low Nb/U ratios, these features suggest that the lithospheric mantle source was metasomatized by subduction-related fluids beneath the Lüchun-Jinping microblock. The relatively high Rb/Sr ratios and high heavy rare-earth element contents indicate that these lamprophyres were derived from partial melting of a phlogopite-bearing lherzolite within the spinel stability field. The parental magmas have experienced fractional crystallization of olivine and clinopyroxene during emplacement. Comprehensive comparisons between the lamprophyres from the Lüchun-Jinping microblock and the potassic-ultrapotassic mafic rocks from the western Yangtze Craton indicate that the Lüchun-Jinping microblock can be regarded as a dismembered part of the western Yangtze Craton due to continental extrusion and Cenozoic sinistral displacement. The compositional trends of the potassic-ultrapotassic mafic rocks suggest that the palaeogeographic position of the Lüchun-Jinping microblock was near the Dali area (west of the Binchuan) and close to the Jinshajiang suture zone before the Cenozoic

Dietary Intake of Fatty Acids, Total Cholesterol, and Stomach Cancer in a Chinese Population.

To investigate the associations between dietary fatty acids and cholesterol consumption and stomach cancer (SC), we analyzed data from a population-based case-control study with a total of 1900 SC cases and 6532 controls. Dietary data and other risk or protective factors were collected by face-to-face interviews in Jiangsu Province, China, from 2003 to 2010. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multiple unconditional logistic regression models and an energy-adjusted method. The joint associations between dietary factors and known risk factors on SC were examined. We observed positive associations between dietary saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and total cholesterol and the development of SC, comparing the highest versus lowest quarters. Increased intakes of dietary SFAs (p-trend = 0.005; aOR, 1.11; 95% CI, 1.01-1.22 with a 7 g/day increase as a continuous variable) and total cholesterol (p-trend &lt; 0.001; aOR, 1.13; 95% CI, 1.06-1.22 with a 250 mg/day increase as a continuous variable) were monotonically associated with elevated odds of developing SC. Our results indicate that dietary SFAs, MUFAs, and total cholesterol are associated with stomach cancer, which might provide a potential dietary intervention for stomach cancer prevention

Spatial beam self-cleaning in bi-tapered multimode fibers

We report the spatial beam self-cleaning in bi-tapered conventional multimode fibers (MMFs) with different tapered lengths. Through the introduction of the bi-tapered structure in MMFs, the input beam with poor beam quality from a high-power fiber laser can be converted to a centered, bell-shaped beam in a short length, due to the strengthened nonlinear modes coupling. It is found that the bi-tapered MMF with longer tapered length at the same waist diameter shows better beam self-cleaning effect and larger spectral broadening. The obtained results offer a new method to improve the beam quality of high-power laser at low cost. Besides, it may be interesting for manufacturing bi-tapered MMF-based devices to obtain the quasi-fundamental mode beam in spatiotemporal mode-locked fiber lasers